Method for producing porous materials.



C. F. S I DERVALL & H. HELIN.

METHOD FOR PRODUCING POROUS MATERIALS.

APPLICATION FILED AUG-211912} 1,235,071 Patented Jul 31, 1917.

ATT IVE U ares rant:

CABI- FREIDEIK SDEBVALL, (3F KILSMO, AND HEMING HELIN, 0F SKABBLAGKA, SWEDEN.

METHOD FOR PRODUCING ?OROUS MATERIALS.

Lesson.

Specification of Letters Patent.

Patented July 31, 191'? Application filed August 2, 1912. Serial No. 712,877.

and also act on the fibers of the pulp as economically as possible.

A means :Eor' carrying out the process 18 shown U]. the accompanying drawing which isa section through a mold containing ironturnings and magnesium carbonate.

According to the present invention wire-' network, iron turnings or such meltable objeots are placed in the mold employed for casting the working parts in question, so that the molten metal when poured into the mold becomes agitated, by which action a flaw-formation is caused, which makes the metal-mass porous. This flaw-formation can be increased by mixing the molten metal with calcic or magnesium-carbonate or other gasgiving substances, which by the formin of gas produces flaws in the material an make it porous.

Preferably the method is so carried out by placing the-iron turnings or' the wirenetwork in the molds at a suitable distance from each other, after which the molten metal is poured into the molds. WVhen it comes in contact'with the objects put into the mold, the temperature of which is lower than the molten metal, the latter'becomes agitated, causing a flaw-formation in the material and making the latter porous. If

gasgiving substances are to be used, they are placed'upon the iron turnings, wirenetworks or the like.

It is obvious, that material made in the above manner possesses the durability of steel, and that, when used in breaking engines, wood-pulp mills and similar apparatus intended for grinding wood-pulp,there will be no danger of damaging the fibers of the wood-pulp owing to the porous structure.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is:

.1. A method of forming working parts for apparatus intended for grinding Woodpulp, consisting in placing a gas producing substance in the mold and then pouring the molten metal into the mold, whereby there will be an agitation producing flaws in the material as it hardens, thereby rendering it porous. v I

2. A method of forming working parts for apparatus intended for grinding woodpulp, consisting in placing meltable objects spaced from one another in the mold, placing a gas producing substance within said mold and upon said objects, and then pouring the molten metal into the mold, whereby there will be an agitation and formation of gas producing flaws in the material, thereby rendering it porous.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses. 

